P0301 code - running a bit rough

[guycar778]

Hi all,

My 2002 Yukon is running a bit poorly these days.

It's got 250,000 kms (roughly 155,000 mi) and maintenance history is largely unknown. I've had it for about 15,000 of those kms and haven't done much other than oil changes.

Started hesitating under load a couple months ago. Just a bit of stuttering at freeway speeds when I give it a bit of gas. Got a bit worse this week. Got flashing check engine lights, and now a steady check engine light. Pulled a P0301 code (misfire cylinder #1).

Initial plan is to replace spark plugs and wires. I have no idea if they're original or have ever been changed. Can't hurt things. Hoping they fix the problem.

Is there anything else I can / should check before ordering the parts?

I'm not driving it much now that I've gotten the check engine lights.

 

[DRG]

I believe your engine is coil on plug, so not distributor cap or rotor to worry about. I'd go for the cheapest stuff first!

If you suspect plugs and wires, swap them to another cylinder and see if the code follows, the only cost is your effort.

Lot's of info online, I just typed in P0301. Found the following on yourmechanic.com

What causes the P0301 code?

• Faulty spark plug in cylinder 1
• No compression in cylinder 1
• Damage or excessive wear of spark plug wires and/or coils
• Damage or excessive wear of distributor cap (not applicable to all vehicles)
• Damage or excessive wear of rotor button (not applicable to all vehicles)
• Faulty fuel injector
• Clogged EGR valves or tubes
• Burned valves
• Inaccurate ignition timing
• Vacuum leaks
• Low fuel (rare)
• Leaking from head gasket
• Cracked distributor cap
• Faulty camshaft sensor
• Faulty crankshaft sensor
• Faulty mass air flow sensor
• Faulty oxygen sensor
• Faulty throttle position sensor
• Faulty catalytic converter
• Faulty powertrain control module

 

[1_8TTony]

The ignition system on these engines are not a "Coil on Plug" design.........they are individual coils mounted on a plate above the valve cover. Four coils per side. This design is called "Remote Mount Coil".

Plugs and wires for these engines will easily cost over a hundred dollars. The plugs are platinum and can last a hundred thousand miles. The plug wires are so short that they hardly ever fail and are also good for hundred thousand miles.

Before you spend any money.......If I were you.......I would swap the coil plate assemblies since they both are identical and have identical wire harness sockets. After you swap the coil plate assemblies, clear the code and see what happens. If you get the code P0308 (misfire cylinder #8), you will infact know that a particular coil is bad.

 

[01ssreda4]

Get the NGK/MSD combo from scoggin dickey.

http://ls1tech.com/forums/sponsor-sales-specials/1675529-msd-plug-wires-free-ngk-plugs.html